The invention relates to a folding rigid caravan with assisted erection and, relates more particularly, to methods for mounting its resilient erecting elements.
Folding rigid caravans with assisted erection are known. These comprise a base carried by a chassis defined by a floor and four substantially vertical lower panels, namely end panels (front and rear) and side panels (right and left); four upper panels, namely end panels (front and rear) and side panels (right and left), pivotal about horizontal axes at the upper free edge of the lower panels and disposed respectively either substantially horizontally in the upper opening of the base or substantially vertically as extensions of the corresponding lower panels when the caravan is folded or completely erected; and a roof pivotally connected to the upper end panels by means of rollers having axes corresponding to the upper horizontal edges of the upper end panels, cooperating with slideways in the roof which rests horizontally either on the base or on the upper panels when the caravan is folded or completely erected. At least one and generally more unidirectional resilient erecting elements such as jacks, for example pneumatic jacks, are each articulated to the base and an upper panel particularly, an end panel, with a view to urging this panel to pivot permanently in the direction of erection of the caravan.
In a first embodiment (French Pat. No. 2,284,480) the erecting elements are disposed permanently and entirely outside the caravan and, at least when it is erected, across the horizontal plane defined by the pivotal axes of the upper side panels, hereinafter called plane P. This arrangement permits the location of the erecting elements with the proper inclination for conferring on them maximum efficiency, but on the other hand they are visible on the exterior of the caravan and are subject to shocks. As a variation (French Pat. No. 2,296,545), the erecting elements are partially located in a casing arranged as an extension of the caravan base with consequent drawbacks.
In a second embodiment, the erecting elements are disposed permanently and entirely inside the caravan that is to say the space defined by the base, the upper panels and the roof. Three variations of this construction have been proposed.
In the first construction (French Pat. No. 2,355,692), the erecting elements are located permanently and entirely above plane P and are articulated to the base by cranked members of L-form in order not to hinder pivoting of the side panels once the end panels are raised. This construction is thus complex, costly, non-aesthetic (since the erecting elements are located opposite the upper panels) and dangerous since if the upper end panels are not in their correct position, the upper side panels can interfere with the erecting elements.
In the second construction, the erecting elements are located across plane P. Thus in order to allow pivoting of these panels, at least one of the pivotal connections of each erection element is removable which has the drawback of being non-aesthetic, poorly designed and not very reliable.
In the third construction (French Pat. No. 2,263,907) the erecting elements are located permanently and entirely above plane P. To allow for pivoting, the upper side panels are connected to the base by hinges with offset axes, which has the drawback of being non-aesthetic, costly and unsatisfactory.
In the three constructions, a space for the passage of the erecting element is provided between each vertical edge of the upper side panels and the internal face of the adjacent upper end panel. This space is concealed, when the caravan is erected, by a batten securely fixed to the upper end panel on its internal face and along its edge. It is thus equally necessary to provide a housing space for these battens when the caravan is erected. For example, the upper edges of the lower end panels are disposed above those of the lower side panels and the base thus has a non-aesthetic step in the region of its opening, creating problems of weather-tightness and necessitating that the roof be provided with a vertical depending edge forming a cover masking this stepping. This depending edge is equally essential to rigidify the roof due to insufficient seating on the base. This weighting of the roof requires the provision of more powerful erecting elements and creates numerous other problems in manufacture and usage of the caravan.
Thus, known constructions of folding rigid caravans with assisted erection are not very satisfactory insofar as the erecting elements are concerned.